At present, mobile communication terminals (called as mobile terminals for short) we use can be classified into the following several types according to structural shape: open-faced type, double-cover type, slide type, rotary type, and so on, and the slide type mobile terminal is a focus of the present invention.
With a progress of information technology and times, mobile terminals have become a necessary of people's lives, and has increasingly abundant application functions, not only the most basic communication functions, but also some auxiliary functions such as Global Position System (GPS), Bluetooth (BT), Wireless Fidelity (WIFI) are gradually developed to common must-have functions.
In order to receive and send a useful radio communication signal, an antenna is needed to be installed in the mobile terminal, and the antennas can be classified into built-in type antennas and external type antennas according to the installation structure of the antenna in the mobile terminal. For needs of attractive appearance, being practical and compactness, almost all the current mobile terminals adopt the built-in antennas; for a slide-type mobile terminal in general, the antenna is designed to be installed in the lower slide portion of the mobile terminal, which is mainly based on the consideration that a Flexible Printed Circuit board connecting the upper slide portion and the lower slide portion is not suitable for transmitting a high-frequency signal (such as a GPS signal received by a GPS antenna, a Bluetooth signal received and sent by a Bluetooth antenna and so on), and a metal slide rail between the upper slide portion and the lower slide portion will also have a greater impact on the antenna located on the top of the lower slide portion, which causes decrease of its performance relative to those open-faced or double-cover mobile terminals.
A form of a built-in antenna of a slide-type mobile terminal will be described as follows referring to a schematic diagram shown in FIG. 1 of a structure of a slide-type mobile terminal in the existing technology.
FIG. 1 shows a front view of a slide-type mobile terminal and side sectional views of the mobile terminal with its lower slide portion is in open state and closed state respectively. As shown in the figure, the slide-type mobile terminal in the existing technology includes:
a lower slide portion 101, which is configured with a main Printed Circuit Board (PCB) 102 used to control main functions of the mobile terminal, and some the mobile terminal components;
an upper slide portion 103, which is equipped with a mobile terminal component for implementing audio-video functions and a auxiliary PCB 104 for implementing other auxiliary functions.
The upper slide portion 103 may perform a slide relative to the lower slide portion 101, to implement an opening and closure of the lower slide portion 101. The upper slide portion 103 is connected with the lower slide portion 101 by a FPC, when the FPC is in a bending state, the upper slide portion 103 and the lower slide portion are overlapped, and the lower slide portion 101 is closed; when the upper slide portion 103 slides away relative to the lower slide portion along the metal slide rail in a length direction, the FPC is in a unfolded state, and now the lower slide portion 101 is open.
Wherein, a main antenna 105 used for implementing receiving and transmitting a communication signal is located in the bottom of the lower slide portion 101, and a GPS antenna 106 (auxiliary antenna) used for implementing GPS function is located on the top of the lower slide portion 101.
In general, either of the main antenna and the auxiliary antenna (such as a GPS antenna, a Bluetooth antenna and so on) is located in the lower slide portion 101 but not in the upper slide portion 103. If the main antenna and the auxiliary antenna are located in the upper slide portion 103, then a high-frequency signal generated by the main PCB 102 installed in the lower slide portion 101 can not be well transmitted to the upper slide portion 103, and a high-frequency signal received by the built-in antenna of the upper slide portion can not be well transmitted to the lower slide portion; if the main PCB 102 located in the lower slide portion 101 and the antenna located in the upper slide 103 are respectively connected with a coaxial cable with small energy loss, then flexibility and reliability of the coaxial cable when the lower slide portion 101 is in an open state and an closed state can not yet be ensured in the structure design; meanwhile, the coaxial cable is liable to be broken when the lower slide portion 101 is open and closed back and forth, so the transmission of the high-frequency signal between the upper slide portion and the lower slide portion can also not be ensured; while if the high-frequency signal is transmitted by the FPC connecting the upper slide portion and the lower slide portion, it will be vulnerable to interferences from other signals, and has greater loss which will greatly decrease performance of the antenna, even the functions of antenna can not be implemented. The above many factors make the location area of the antennas (including the main antenna and the auxiliary antenna) of the slide-type mobile terminal is limited to the lower slide portion 101.
In a design of a more and more popular multi-band multi-function mobile terminal, the mode of locating the antenna in the lower slide portion 101 will bring a lot of constraints to the design: a design of locating all of a plurality of multi-band multi-function antennas in the lower slide portion 101 generally causes a tight layout space of the lower slide portion 101 and constraints on the shape-design of the mobile terminal.